Structure and formation method of chip package with lid

ABSTRACT

Structures and formation methods of a chip package are provided. The chip package includes a substrate and a semiconductor die over a surface of the substrate. The chip package also includes a lid over the semiconductor die. The lid has a number of support structures bonded with the substrate, and the lid has one or more openings between two of the support structures.

BACKGROUND

The semiconductor integrated circuit (IC) industry has experienced rapidgrowth. Continuing advances in semiconductor manufacturing processeshave resulted in semiconductor devices with finer features and/or higherdegrees of integration. Functional density (i.e., the number ofinterconnected devices per chip area) has generally increased whilefeature size (i.e., the smallest component that can be created using afabrication process) has decreased. This scaling-down process generallyprovides benefits by increasing production efficiency and loweringassociated costs.

A chip package not only provides protection for semiconductor devicesfrom environmental contaminants, but also provides a connectioninterface for the semiconductor devices packaged therein. One smallertype of packaging for semiconductor devices is a chip-scale package(CSP), in which a semiconductor die is placed on a substrate.

New packaging technologies have been developed to further improve thedensity and functions of semiconductor dies. These relatively new typesof packaging technologies for semiconductor dies face manufacturingchallenges.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It shouldbe noted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIGS. 1A-1C are cross-sectional views of various stages of a process forforming a chip package, in accordance with some embodiments.

FIG. 2 is a perspective view of a chip package, in accordance with someembodiments.

FIG. 3 is a top view of a chip package, in accordance with someembodiments.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

Some embodiments of the disclosure are described. Additional operationscan be provided before, during, and/or after the stages described inthese embodiments. Some of the stages that are described can be replacedor eliminated for different embodiments. Additional features can beadded to the semiconductor device structure. Some of the featuresdescribed below can be replaced or eliminated for different embodiments.Although some embodiments are discussed with operations performed in aparticular order, these operations may be performed in another logicalorder.

FIGS. 1A-1C are cross-sectional views of various stages of a process forforming a chip package, in accordance with some embodiments. FIG. 2 is aperspective view of a chip package, in accordance with some embodiments.In some embodiments, FIG. 2 shows a perspective view of the structureshown in FIG. 1B or FIG. 1C. FIG. 3 is a top view of a chip package, inaccordance with some embodiments. In some embodiments, FIG. 3 shows atop view of the structure shown in FIG. 1B, 1C, or 2.

As shown in FIG. 1A, a substrate 100 is received or provided. In someembodiments, the substrate 100 is a circuit board. The substrate 100 mayserve as an interposer providing electrical connection routes betweenelements disposed on opposite surfaces of the substrate 100.

The substrate 100 may include a dielectric material such as an organicmaterial. The organic material may be PP (Polypropylene) with glassfiber, epoxy resin, polyimide, cyanate ester, another suitable material,or a combination thereof. Multiple conductive features (not shown) areformed in the substrate 100.

The conductive features may include conductive lines that provideelectrical connections in horizontal directions and/or conductive vias(or plugs) that provide electrical connections in vertical directions.The conductive features may be made of a metal material, such as copper,aluminum, tungsten, titanium, cobalt, gold, platinum, tin, anothersuitable material, or a combination thereof.

Multiple deposition or coating processes, patterning processes, andplanarization processes may be used to form the substrate 100. Thedeposition or coating processes may include a spin-on process, achemical vapor deposition (CVD) process, a physical vapor deposition(PVD) process, an electroplating process, an electroless platingprocess, an atomic layer deposition (ALD) process, a spray coatingprocess, another applicable process, or a combination thereof. Thedeposition or coating processes may be used to form dielectric layersand conductive layers of the substrate 100.

The patterning processes may include a photolithography process, anetching process, a laser drilling process, a mechanical drillingprocess, another applicable process, or a combination thereof. Thepatterning processes may be used to form feature openings that are usedto contain the conductive features. For example, the feature openingsinclude trenches and via holes. The trenches may be used to containconductive lines in the substrate 100, and the via holes may be used tocontain conductive vias or conductive plugs of the substrate 100.

The planarization process may include a chemical mechanical polishing(CMP) process, a grinding process, a dry polishing process, an etchingprocess, another applicable process, or a combination thereof. Theplanarization process may be used to remove excess conductive layers toprovide a substantially planar surface, which facilitate to subsequentformation processes.

Many variations and/or modifications can be made to embodiments of thedisclosure. In some other embodiments, the substrate 100 is asemiconductor substrate with multiple conductive features formedtherein. In some embodiments, the substrate 100 is a semiconductorinterposer, such as a silicon interposer.

Afterwards, one or more semiconductor dies (such as a semiconductor die102) are mounted over the substrate 100, as shown in FIG. 1A inaccordance with some embodiments. In some embodiments, various deviceelements are formed in the semiconductor die 102. Examples of thevarious device elements include transistors (e.g., metal oxidesemiconductor field effect transistors (MOSFET), complementary metaloxide semiconductor (CMOS) transistors, bipolar junction transistors(BJT), high voltage transistors, high frequency transistors, p-channeland/or n-channel field effect transistors (PFETs/NFETs), etc.), diodes,or other suitable elements.

The device elements are interconnected to form integrated circuitdevices. The integrated circuit devices include logic devices, memorydevices (e.g., static random access memories, SRAMs), radio frequency(RF) devices, input/output (I/O) devices, system-on-chip (SoC) devices,other applicable types of devices, or a combination thereof. In someembodiments, the semiconductor die 102 is a system-on-chip (SoC) chipthat includes multiple functions.

In some embodiments, multiple conductive elements 104 are formed betweenthe semiconductor die 102 and the substrate 100, as shown in FIG. 1A.The conductive elements 104 form electrical connections between thedevice elements in the semiconductor die 102 and the conductive featuresformed in the substrate 100. For example, each of the conductiveelements 104 may be in electrical contact with a corresponding pad (notshown) formed on the substrate 100. There may be multiple pads formed onthe substrate 100. The pads may be wider portions of the conductivefeatures formed on the substrate or embedded in the substrate 100.Therefore, the device elements in the semiconductor die 102 may beelectrically connected to elements that will be formed on the oppositesurface of the substrate 100 through the conductive elements 104 and theconductive features in the substrate 100.

In some embodiments, the conductive elements 104 include solder bumps,metal bumps, other suitable structures, or a combination thereof. Theconductive elements 104 may include a combination of a solder materialand a metal pillar. Each of the conductive elements 104 may include acopper pillar and a solder portion connecting the pads of the substrate100. For example, a number of copper pillars are formed on conductivepads (not shown) of the semiconductor die 102 through an electroplatingprocess or another applicable process. Afterwards, a solder material isused to bond the copper pillars with the pads of the substrate. Athermal operation may be performed to reflow the solder material. As aresult, the conductive elements 104 including the copper pillars and thesolder portion are formed.

Many variations and/or modifications can be made to embodiments of thedisclosure. In some other embodiments, the conductive elements 104 arenot formed. In some embodiments, the semiconductor die 102 is directlybonded on the substrate 100. In some embodiments, the conductive pads ofthe semiconductor die 102 are in electrical contact with the pads of thesubstrate 100.

In some embodiments, a protection layer 106 is formed on the substrate100 to surround the conductive elements 104, as shown in FIG. 1A. Theprotection layer 106 may be used to prevent the conductive elements 104from oxidation or being damaged. In some embodiments, an underfillmaterial is disposed or injected between the substrate 100 and thesemiconductor die 102 to form the protection layer 106. Embodiments ofthe disclosure are not limited thereto. In some other embodiments, theprotection layer 106 is not formed.

As shown in FIGS. 1B, 2, and 3, a lid 112 is placed over the substrate100 and the semiconductor die 102, in accordance with some embodiments.The lid 112 may act as a stiffener to prevent the substrate 100 fromwarping or to reduce the warpage of the substrate 100. The lid may alsofunction as a thermal conductive element. Therefore, not only are thestructural strength and reliability of the chip package enhanced, butthe dissipation of heat generated during the formation and operation ofthe chip package is also improved.

In some embodiments, the lid 112 is made of a metal material. The metalmaterial may include copper, aluminum, silver, gold, platinum, steel,another suitable material, or a combination thereof. In someembodiments, the lid 112 is a single-layered structure. For example, thelid is made from an aluminum foil or copper foil. However, embodimentsof the disclosure are not limited thereto. In some other embodiments,the lid 112 is a multilayer structure including a number of sub-layers.In some embodiments, the sub-layers are made of the same material. Insome other embodiments, some of the sub-layers are made of differentmaterials.

As shown in FIGS. 1B and 2, the lid 112 includes an upper plate 111 tand a number of support structures including support structures 113 a,113 b, 113 c, and 113 d, in accordance with some embodiments. In someembodiments, the upper plate 111 t and the support structures 113 a-113d have substantially the same thickness. The thickness may be in a rangefrom about 0.15 mm to about 0.25 mm. In some embodiments, each of thesupport structures 113 a-113 d has a sidewall 111 s that connects theupper plate 111 t. The sidewall 111 s may be a slanted sidewall.

In some embodiments, the lid 112 is secured to or bonded with thesemiconductor die 102 and the substrate 100, as shown in FIG. 1B. Insome embodiments, the upper plate 111 t of the lid 112 is secured to thesemiconductor die 102 through a thermal interface element 108. In someembodiments, each of the support structures 103 a-103 d of the lid 112is secured to the semiconductor die 102 through an adhesive element 110.In some embodiments, the thermal interface element 108 is in directcontact with the semiconductor die 102. In some embodiments, the thermalinterface element 108 is in direct contact with the semiconductor die102 and the lid 112.

The thermal interface element 108 may function as a thermal conductor(or heat sink) to dissipate heat from the semiconductor die 102. Thethermal interface element 108 may also be used as an adhesive element tobond the lid 112 with the semiconductor die 102. In some embodiments,the adhesive element 110 also functions as a thermal conductor. In someembodiments, materials of the thermal interface element 108 and theadhesive element 110 are the same. However, many variations and/ormodifications can be made to embodiments of the disclosure. In someother embodiments, materials of the thermal interface element 108 andthe adhesive element 110 are different from each other.

In some embodiments, the upper plate 111 t extends beyond edges 101 ofthe semiconductor die 102, as shown in FIG. 1B. As shown in FIG. 3, thesemiconductor die 102 is completely covered by the lid 112 from a topview, in accordance with some embodiments.

As shown in FIG. 2, the lid 112 has one or more openings includingopenings 115 a, 115 b, 115 c, and 115 d, in accordance with someembodiments. In some embodiments, each of the openings 115 a-115 d isbetween two of the support structures. As shown in FIG. 2, the opening115 a is between the support structures 113 a and 113 d. The opening 115b is between the support structures 113 b and 113 d. The opening 115 cis between the support structures 113 b and 113 c. The opening 115 d isbetween the support structures 113 a and 113 c.

In some embodiments, the opening 115 a extends from the supportstructure 113 a towards the support structure 113 d. In someembodiments, the opening 115 a extends from the upper plate 111 ttowards the substrate 100. In some embodiments, the opening 115 aextends to the substrate 100. As shown in FIG. 2, edge portions of thesubstrate 100 (that are between the corner portions) are exposed withoutconnecting the lid 112.

In some embodiments, the opening 115 a is surrounded by an edge of theupper plate 111 t and edges of the sidewalls 111 s of the supportstructures 113 a and 113 d, as shown in FIG. 2. In some embodiments,each of the openings 115 a-115 d penetrates through the lid 112. In someembodiments, each of the openings 115 a-115 d exposes the substrate 100.

In some embodiments, the lid 112 has four openings, as shown in FIG. 2.In some embodiments, the positions of the openings 115 a-115 d of thelid 112 are symmetrical with each other, as shown in FIG. 2. However,embodiments of the disclosure are not limited thereto. In some otherembodiments, one or some of the openings of the lid 112 are notsymmetrical with other openings.

Many variations and/or modifications can be made to embodiments of thedisclosure. In some embodiments, the lid 112 has more than fouropenings. In some other embodiments, the lid 112 has less than fouropenings.

In some embodiments, shapes and/or sizes of the openings of the lid 112are substantially the same, as shown in FIG. 2. However, embodiments ofthe disclosure are not limited thereto. Many variations and/ormodifications can be made to embodiments of the disclosure. In someother embodiments, shapes and/or sizes of some openings of the lid 112are different from those of other openings of the lid 112.

In some embodiments, the lid 112 is partially removed to form theopenings 115 a-115 d. The openings 115 a-115 d may be formed using alaser cutting process, a mechanical cutting process, an etching process,another applicable process, or a combination thereof. In someembodiments, the openings 115 a-115 d are formed before the lid 112 isbonded with the semiconductor die 102 and the substrate 100. However,embodiments of the disclosure are not limited thereto. Many variationsand/or modifications can be made to embodiments of the disclosure. Insome other embodiments, the openings 115 a-115 d are formed after thelid 112 is bonded with the semiconductor die 102 and the substrate 100.

As shown in FIGS. 1B, 2, and 3, the support structures 113 a-113 d arepositioned on corner portions of the substrate 100, in accordance withsome embodiments. In some embodiments, the substrate 100 has four cornerportions, as shown in FIGS. 2 and 3. The support structures 113 a-113 dare on the four corner portions of the substrate 100.

However, embodiments of the disclosure are not limited thereto. Manyvariations and/or modifications can be made to embodiments of thedisclosure. In some embodiments, the lid 112 has more than four supportstructures. In some other embodiments, the lid has less than foursupport structures. In some other embodiments, some of the supportstructures are positioned on portions of the substrate 100 that areother than the corner portions. In some other embodiments, some of thecorner portions of the substrate 100 are not covered by the supportstructures.

As shown in FIG. 3, the substrate 100 has a length L₁ and a length L₂.The lid 112 has a length L₃ and a length L₄. In some embodiments, thelength L₁ is greater than the length L₃, and the length L₂ is greaterthan the length L₄. In some embodiments, the difference between thelength L₁ and the length L₃ is in a range from about 0.5 mm to about 1mm. For example, the difference between the length L₁ and the length L₃is about 0.7 mm. In some embodiments, the difference between the lengthL₂ and the length L₄ is in a range from about 0.5 mm to about 1 mm. Forexample, the difference between the length L₂ and the length L₄ is about0.7 mm.

As shown in FIG. 3, each of the support structures 113 a-113 d haslengths L₅ and L₆. The length L₅ may be about 0.25 times the length L₃.The length L₆ may be about 0.25 times the length L₄. As shown in FIG. 3,the upper plate 111 t has lengths L₇ and L₈. The length L₇ may be about0.8 times the length L₃. The length L₈ may be about 0.8 times the lengthL₄.

Afterwards, a number of conductive bumps 114 are formed on a surface ofthe substrate opposite to the surface where the semiconductor die 102and the lid 112 are disposed, as shown in FIG. 1C in accordance withsome embodiments. In some embodiments, the conductive bumps 114 includesolder bumps, metal bumps, other suitable structures, or a combinationthereof. The conductive bumps 114 may include a combination of a soldermaterial and a metal pillar. In some embodiments, one or more of theconductive bumps 114 are electrically connected to the device elementsof the semiconductor die 102 through some of the conductive featuresformed in the substrate 100 and some of the conductive elements 104.

In some embodiments, one or more semiconductor dies 116 are mounted onthe opposite surface of the substrate 100, as shown in FIG. 1C. In someembodiments, conductive elements 118 and a protection layer 120 areformed between the substrate 100 and one of the semiconductor dies 116.The material and formation method of the conductive elements 118 and theprotection layer 120 may be similar to those of the conductive elements104 and the protection layer 106. In some embodiments, some deviceelements in the semiconductor dies 116 and 102 are electricallyconnected to each other.

During the formation of the chip package, some processes are performedat a high temperature. For example, the formation of the conductiveelements 104 and 118 and the conductive bumps 114 involves hightemperature processes, such as reflow processes. Due to the coefficientof thermal expansion (CTE) mismatch between different elements (such asbetween the thermal interface element 108 and the lid 112), a warpage ofthe chip package might occur. In some embodiments, due to the lid 112,the warpage of the chip package is kept at an acceptable amount.

In some embodiments, due to the openings 115 a-115 d, the thermal stressbetween the substrate 100 and the lid 112 may be released. Delaminationbetween the support structures 113 a-113 d and the substrate 100 orbetween the upper plate 111 t and the semiconductor die 102 isprevented. The warpage of the chip package is also significantlyreduced. In some embodiments, an average warpage of the chip package isreduced to be lower than about 43 μm. In some other cases, the lid 112does not have support structures or does not have openings. The averagewarpage of the chip package may be greater than about 59 μm or evengreater than about 81 μm.

Embodiments of the disclosure form a lid over a substrate to protect asemiconductor die between the lid and the substrate. The lid is bondedwith or secured to the semiconductor die and the substrate and functionsas a stiffener and/or a heat sink. The lid has one or more openingsformed between an upper plate of lid and the substrate. The openings mayreduce thermal stress between the lid and the substrate. Delaminationand warpage of the chip package are significantly reduced. Therefore,the reliability and performance of the chip package are improved.

In accordance with some embodiments, a chip package is provided. Thechip package includes a substrate and a semiconductor die over a surfaceof the substrate. The chip package also includes a lid over thesemiconductor die. The lid has a number of support structures bondedwith the substrate, and the lid has one or more openings between two ofthe support structures.

In accordance with some embodiments, a chip package is provided. Thechip package includes a substrate and a semiconductor die over thesubstrate. The chip package also includes a lid secured to thesemiconductor die and the substrate. The lid has an opening penetratingthrough the lid.

In accordance with some embodiments, a chip package is provided. Thechip package includes a substrate and a semiconductor die mounted on thesubstrate. The chip package also includes a metal lid having an upperplate and a number of support structures. The upper plate is bonded withthe semiconductor die, and the support structures are bonded with thesubstrate.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

1. A chip package, comprising: a substrate; a semiconductor die over anupper surface of the substrate; and a lid over the semiconductor die,wherein the lid has a plurality of support structures bonded with thesubstrate, the support structures are positioned on corner portions ofthe substrate, at least one opening is between two of the supportstructures, the at least one opening penetrates through the lid toexpose a space containing the semiconductor die, and an entirety of atop surface of the semiconductor die is covered by the lid. 2.(canceled)
 3. The chip package as claimed in claim 1, further comprisinga thermal interface element between the lid and the semiconductor die.4. The chip package as claimed in claim 3, wherein the thermal interfaceelement is in direct contact with the lid and the semiconductor die. 5.The chip package as claimed in claim 3, further comprising an adhesiveelement between the substrate and one of the support structures of thelid.
 6. The chip package as claimed in claim 5, wherein materials of thethermal interface element and the adhesive element are the same.
 7. Thechip package as claimed in claim 1, wherein the opening exposes thesubstrate.
 8. The chip package as claimed in claim 1, wherein the lid ismade of a metal material.
 9. The chip package as claimed in claim 1,further comprising a plurality of conductive bumps disposed on a lowersurface of the substrate opposite to the upper surface of the substrate.10. The chip package as claimed in claim 1, wherein the supportstructures are on four corner portions of the substrate.
 11. A chippackage, comprising: a substrate; a semiconductor die over thesubstrate; and a lid secured to the semiconductor die and the substrate,wherein the lid has a plurality of support structures secured to thesubstrate, the support structures are positioned on corner portions ofthe substrate, an opening penetrates through the lid to expose a spacecontaining the semiconductor die, and an entirety of a top surface ofthe semiconductor die is covered by the lid.
 12. The chip package asclaimed in claim 11, wherein the lid is secured to the semiconductor diethrough a thermal interface element, and the lid is secured to thesubstrate through an adhesive element.
 13. The chip package as claimedin claim 12, wherein materials of the thermal interface element and theadhesive element are different from each other.
 14. The chip package asclaimed in claim 11, wherein at least one of the support structures hasa slanted sidewall connecting an upper plate of the lid.
 15. The chippackage as claimed in claim 14, wherein the opening is surrounded by anedge of the upper plate of the lid and an edge of the slanted sidewall.16. A chip package, comprising: a substrate; a semiconductor die mountedon the substrate; and a metal lid having an upper plate and a pluralityof support structures, wherein the upper plate is bonded with thesemiconductor die, the support structures are bonded with the substrate,the support structures are positioned on corner portions of thesubstrate, an opening is between two of the support structures, theopening penetrates through the metal lid to expose a space containingthe semiconductor die, and the upper plate of the metal lid completelycovers a top surface of the semiconductor die.
 17. The chip package asclaimed in claim 16, wherein the metal lid has a single-layeredstructure.
 18. The chip package as claimed in claim 16, wherein thesubstrate is a circuit board.
 19. The chip package as claimed in claim16, wherein the upper plate of the metal lid extends beyond edges of thesemiconductor die.
 20. (canceled)
 21. The chip package as claimed inclaim 15, wherein the edge of the upper plate has a portion surroundingthe opening, and the portion of the edge of the upper plate is longerthan each of the support structures.
 22. The chip package as claimed inclaim 11, wherein the opening exposes the substrate.